Magnetic graphene-based nanocomposites as highly efficient absorbents for Cr(VI) removal from wastewater

Environmental Science and Pollution Research - Due to the merits of their high adsorption and convenient separation, magnetic graphene-based composites have become a promising adsorbent in terms of...     

可持续发展网络的作用与前景

可持续发展网络是最近几年随着计算机及网络技术的进步而迅速发展起来的信息网络系统。以地理信息为主要内容的可持续发展网络是调控可持续发展的重要环节，这对可持续发展战略的研究和实践具有重要意义。可持续发展网络建设不但可以将可持续发展研究与实践同地理信息科学更加紧密地结合到一起，同时也将促进地理信息科学和可持续发展研究的进一步发展。     

阴离子表面活性剂—季铵盐—磺酞类染料的显色反应及其应用

本文研究了阴离子表面活性剂(AS),季铵盐(QAS),磷酞类染料(SPD)显色反应的机理,发现QAS分别与AS和SPD形成离子缔合物,SPD与QAS的摩尔比和SPD的三级电离常数pK,(HL~-)有关,AS和QAS的缔合比为1:1.基于这一显色反应,建立了氯化十六烷基吡啶(CPC)-溴甲酚紫(BCP)光度法测定AS的方法.在60μgCPC存在下,十二烷基硫酸钠(SDS)和十二烷基苯磺酸钠(SDBS)分别在0—55μg·10ml~(-1)和0—50μg·10ml~(-1)范围内符合比耳定律,其表观摩尔吸光系数分别为6.88×104~L·mol~(-1)·cm~(-1)和6.34×10~4L·mol~(-1)·cm~(-1).用建立的方法测定了河水和生活废水中的AS,结果满意.     

温度对城市污水厂尾水反硝化MBBR深度脱氮的影响

为解决城市污水厂尾水再生利用时ρ(TN)高的问题,采用反硝化MBBR(移动床生物膜反应器)对城市污水厂尾水进行反硝化脱氮,并重点研究不同温度下分别以聚乙烯和聚丙烯为填料的反硝化MBBR的运行效果. 结果表明:在HRT(水力停留时间)为12 h、温度分别为13、19、25和30 ℃时,NO₃--N去除率和反硝化能力变化不大,聚乙烯和聚丙烯反硝化MBBR的NO₃--N去除率分别为80.1%～85.0%和78.2%～84.0%,二者的反硝化能力分别为6.7～7.1和6.5～7.0 mg/(L·h);较长的HRT弥补了低温时反硝化速率低的不足;随温度增加,生物量逐渐增加,但COD_Cr和DOM(溶解性有机物)的去除率变化不明显. 三维荧光图谱表明,出水中主要的DOM(溶解性有机质)为类色氨酸和类富里酸,聚乙烯和聚丙烯反硝化MBBR对DOM总荧光强度的去除率分别为47.6%～52.5%和24.1%～35.8%. 填料上的微生物以杆菌、丝状菌和球菌为主. 综合考虑脱氮效能和有机物污染物去除效能,聚乙烯和聚丙烯反硝化MBBR深度脱氮的最佳温度均为25 ℃.      

可持续发展的基本理论分析

本文首先从可持续发展的概念与内涵入手,通过对可持续发展的理论分析和系统分析,归纳出了可持续发展的基本特点;并通过对指标体系的研究现状的分析,就可持续发展指标体系的建立原则进行了深入的探讨。     

Effects of pulse current electromagnetic fields on human peripheral lymphocytes

The effects of pulsed current electromagnetic fields (PCEMF) on human peripheral lymphocytes sister chromatid exchanges (SCE), and micronuclei (MN) frequencies were investigated. PCEMF were produced by 8/20 μs pulsed current generation with two model types, a long straight wire and a solenoid. Human peripheral lymphocyte samples were exposed to PCEMF (a pulse per min, and continuing for 1 h). SCE and MN assays were used to evaluate the genotoxic effects. The results indicated that SCE and MN incidences correlated positively with B _m and dB/dt. For the long straight wire model, as B _m reached 8.48 × 10^?2 T and dB/dt = 1.06 × 10⁴ T s^?1, the effect was significant. As B _m reached 1.70 × 10^?1 T and dB/dt = 2.13 × 10⁴ T s^?1, the effect was marked. For the solenoid model, the conditions of significant effect were B _m = 0.264 T and dB/dt = 3.30 × 10³ T s^?1 and B _m = 1.32 T and dB/dt = 1.650 × 10⁴ T s^?1. Data indicated that dB/dt was an important factor in increasing the frequencies of MN and SCE in human peripheral lymphocytes.     

Associations of bisphenol exposure with thyroid hormones in pregnant women: a prospective birth cohort study in China

Environmental Science and Pollution Research - Bisphenols are endocrine disruptor chemicals that disrupt thyroid hormone homeostasis. However, evidence on the effects of bisphenol mixtures on...